South Shore is a boat-access dive site located off Niihau, featuring a diverse underwater topography of reefs, drop-offs, walls, and pinnacles. The site offers consistent visibility of 30 metres. Divers should be prepared for moderate currents that can shift quickly, requiring solid buoyancy control and situational awareness. With depths reaching 20 metres, this site presents significant hazards including strong currents, deep water, and the presence of sharks. All gear and hydration must be managed on the boat, as there are no facilities on site. Due to the challenging conditions, this location is best suited for experienced divers who can maintain awareness throughout the 60-minute dive duration.

Arches is an advanced open-water dive site located off Niihau, featuring a complex topography of reef, wall, cavern, and drop-off structures. Divers navigate depths ranging from 10 to 32 metres, with an average depth of 25 metres. The site is characterised by strong currents and visibility between 30 and 40 metres. Due to the presence of overhead environments within the caverns and significant depth profiles, this site requires advanced buoyancy control and careful gas management. Access is strictly by boat to avoid dangerous surf and shore break zones. Divers should be prepared for potential boat traffic upon surfacing and carry a surface marker buoy.

Lehua Crater is a diverse marine site located off the coast of Niihau, United States. The topography encompasses reef slopes, caves, drop-offs, and artificial reef structures. Divers can explore depths ranging from 15 to 70 metres, with an average depth of 45 metres. Visibility is high, typically spanning 29 to 91 metres. Access is strictly by boat to avoid surf and shore break hazards. Conditions generally feature mild currents, though stronger surges may occur. Due to the depth and potential for entanglement, divers should carry a cutting tool and reef hook. This site is suited for intermediate divers, with typical dive times lasting 60 minutes.

Vertical Awareness is a remote wall and pinnacle site located off Niihau. The topography features a significant drop-off reaching depths of 36 metres, with an average depth of 18 metres. Due to the location 33 kilometres from shore, boat access is required. Divers should be prepared for strong currents and variable visibility ranging from 4 to 38 metres. This site is intended for advanced divers only, given the depth, potential for nitrogen narcosis, and current conditions. Water temperatures remain consistent, ranging between 23C and 27C throughout the year. Boat traffic is a noted hazard in this area.

Mana Crack is an 11-mile long sunken barrier reef located off the coast of Niihau. As the furthest offshore dive site in Hawaii, it features numerous drop points along its length. Due to the absence of moorings and the presence of strong currents, this site is strictly for advanced divers and is accessed exclusively via live boat dives. Visibility at the site varies, ranging from 1 to 30 metres. Water temperatures remain consistent throughout the year, typically between 24C and 27C. Divers should be prepared for challenging conditions at this remote offshore location.